The present invention relates to a device for manufacturing reels of video film, and particularly to a reel holder for a device manufacturing reels of video film by winding video tapes having a certain width on reel hubs. The reel holder supports the reel hubs and drives them by a constant torque transmitted from a drive shaft of the winding device. In particular, the present invention relates to a flangeless-type reel holder wherein a ring-type leaf spring is fitted around the said reel holder in order to provide easy mounting and separation of reel hubs, and the outer rim of a bearing interposed between the said holder and the sleeve which is directly coupled to the holder.
Reels of video film are mainly used as a supply of tapes to be wound on reels of video cassettes. In manufacturing reels of video film, tapes are spliced from a tape by a cutting process and are wound around reel hubs R and coupled to reel holders H and are mounted on drive shafts S of the winding device, thus, several (about 20) reels of video film are manufactured at a time.
Each reel holder is supported by a bearing interposed between its holder body and a sleeve mounted on a drive shaft which drives therewith. The reel holder has an air brake which is adapted to drive the reel holder by a constant torque transmitted from the drive shaft by pressurized air. The outer portion of the reel holder has a support construction enabling the mounting and separation of the reel hub.
As shown in FIGS. 3 and 4, such conventional reel holders include a flange 2 having the diameter larger than the outer diameter of the reel holder 1. The flange 2 is formed at one peripheral edge of the reel holder 1, and adapted to support one side of a reel hub 3. The other side of the reel hub 3 is supported by a coil spring 5 disposed in an annular groove 4 formed between the reel holder 1 and a holder cover 8. The coil spring 5 has three portions slightly protruding from the peripheral surface of the reel holder 1 accordingly, the coil spring 5 supports the reel hub at three protruded portions thereof. In the case of handling several flange-type reel holders, the reel holders have to be manually fitted around the drive shaft, one by one. The produced reels of video film also have to be removed from the drive shaft, one by one consquently, the reel holders are frequently damaged, thereby causing them to be prematurely. Due to the unstable support of the coil spring which supports the reel hub only at three portions thereof, the reel hub may be shaken so that the wound tape may escape from the reel hub, causing it to be damaged. The outer rim of the bearing 7 interposed between the holder 1 and the sleeve 6 is supported by a bearing boss 8' extended from a holder cover 8 which is fixed to the side of the holder by means of a screw. Due to the damage caused by the repeated driving and stopping of the holder, the screw may be released or the bearing boss 8' may be broken.
The above-mentioned disadvantage of conventional reel holders will be overcome by providing a flangeless reel holder. This flangeless reel holder enables automatic mounting and removing of the holder by use of a robot.